Subnetting Example 6

Convert decimal into binary

Example 6:

We have to find out binary value in given decimal number 200 and tell me which class it comes from ?

Note: You should always follow from left to right

Solution:

It comes from class C value given in above

Base position    2^7  2^6  2^5  2^4  2^3  2^2  2^1  2^0
Decimal value   128   64   32    16     8     4      2      1     
Binary value         1      1     0      0      1      0     0       0


After completing we can check by adding all "1"s given below;

128 + 64 + 8 = 200 

Rough note:

We can do this adding method given below;

Decimal calculations                                                         Bit in binary
128 is less than 200                                                                on the bit
128 + 64 = 192 is less than to 200                                          on the bit
128 + 64 + 32 = 224 is greater than 200                                 off the bit
128 + 64 + 0 + 16 = 208 is greater than 200                           off the bit
128 + 64 + 0 + 0 + 8 = 200 is equivalent 200                          on the bit
128 + 64 + 0 + 0 + 8 + 4 = 204 is greater than 200                 off the bit
128 + 64 + 0 + 0 + 8 + 0 + 2 = 202 is greater than 200           off the bit
128 + 64 + 0 + 0 + 8 + 0 + 0 + 1 = 201 is greater than 200     off the bit

This is another way of doing through subtracting method which is done in a simple and easy way given below;

Decimal calculation                                                            Bit in binary
200 - 128 = 72 is less than 200                                                on the bit
72 - 64 = 8 is less than 200                                                      on the bit
8 - 32 cannot be subtracted                                                     off the bit
8 - 16 cannot be subtracted                                                     off the bit
8 - 8 = 0 is less than 200                                                          on the bit
0 - 4 = cannot be subtracted                                                    off the bit
0 - 2 cannot be subtracted                                                       off the bit
0 - 1 cannot be subtracted                                                       off the bit


Therefore, this is our binary value 11001000.